Power hammer construction



May 27, 1952 E. A. SMITH 2,598,455

POWER HAMMER CONSTRUCTION med June ze, 1951 2 SHEETS- SHEET 1 SHELL.

lN/ENTOR. 'EOWASDA-5MITH- May 27, 1952 E. A. sMn-H POWER HAMMERCONSTRUCTION O 2 SHEETS-SHEET 2 Filed June 26, 1951 INVENTOR.EDWARDA-5MII'H.

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Patented May 27, 1952 UNITED svi- ATi-:s PATENT POWER HAMMERCQNSTRUCTIQN Edward A. Smith, Chatham, 1N. .1.,Yassgfnor 'to RaymondConcrete Pile Com-pany, iNeW York, .-N. Y., .a `corperation of NewJerseyApplication June 26, 1951SerialLNo.2,33620 (einigte.)

AThis invention -relates to power hammers particularly adapted, `among4other possibilities, `for use in the installation of :piles Iand thelike. 'The invention will be explained'in connection witha form ofhammer adapted for driving hollow metal cores :such -as are placedinside cf lmetal pile shells Jfor driving the latter into place, butit-will be understood that various features ofthe invention are`adaptedior lother possible uses.

In vpreparing lto drive metal pile shells, itis the general -practice tovsuspend a hollow core from -the boom-of a crane, in a vertical positionabove the vdesired location of the pile, a -stea-m hammer vwith its -ramAalso ybeing suspended 'above the core in `position to drive the coreinto -the earth while its lower rend y-is surrounded by vsucceedingsections of the pile shell. :When the vertical dimension of theconventional type of steam hammer is added-to the height ofthe usualpile lcore, it will be apparent that to secure the necessary head roomfor the assembly, it '-becomesnecessary -to use a crane withavery Alongboom-and the Whole assembly becomes very cumbersome and inconvenient -tohandle.

Heretofore in some instancesefforts have been made to provide va -moreconvenient assemblyrequil-ing `less head -room Aby using a single pistonhammerfand ramof afsizevto twithin'the upperend ofthe core. However,such'an arrangement has 'two serious disadvantages, -rst, because lofthe `necessity of using a steam cylinder small enoughito 'bereceived-within the limiteddiameter of the core, the `power -of "thehammerand the consequent-maximum possible Weight of the -ram are'undulylimited, fand secondly, such lsingle piston hammers can deliver yonly alimited -number of blows `per minute 'as compared -with the doublepiston-differential typesof hammers often used fior rapid'pile driving.For these '-reasons the assembly of a single acting hammer `within acore permits lonly comparatively slow pile driving,Withtheresultthat-such an arrangementis ordinarily 'useful only Aonvsmall jobs Wherethe saving cost of moving `the equipment to andfrom'the job VVis more important than the cost-of the actualpiledriving.

lv'The present invention avoids these vdifficulties and involves Ynovelarrangements permitting powerful rapidly operating double acting types oigharnmers andvdiierentialxtypes of hammers to be :constructed andadapted `to be arranged `in assembly .with the upper end of a pile corewith the Ventire ram as well as-the greater'part of the remainder of theYhammer mounted 'within the upper end of the core, thus minimizing "therequired head -room for-the core and'hammer assembly, yet permittingfull advantage to'vbeV taken of Y theuse 'ci -double acting ordifferential typesgf hammers. Y y

The ope'ration as Awell as 'the shapeof 4such double acting anddifferential types of lhammers as heretofore -constructed are such -thatAfor-several reasons hereinafter brought'out, they could not in practicelbe mounted to 4operate withinithe conventional typeof 'pile core. Mcrespecifically, the j'present invention relates to various features makingpossible for the frst 'time the assembly and yoperation of these general*types of lfiavrnm-eur's within the -u-pper endgof a `c ore yor thelike.

Further objects, features Ivandiiclvantages orf the inventionv hereof`will appear from the Jdetailed description given below, taken inconnection with the accompanying drawings iwhich forma part of thisspecification and illustrate fby way of exampie,preferred embodiments ofthe invention.

Inthe drawings:

Fig. 1 is an elevational view, partly --section, showing the' upper endportionsof a pile'core with a double tpistonsteam hammer assembledtherewith inaccordancewiththe invention;

Eig. 2 is an elevational view of one offthepile cores alone and showingan lupper 4end :portion thereon Aconsiaucted `in vaccordance with thepresent invention;

Fig. '3 'is lan elevational viewoi a typical metal pile 4shellwhich isto beidrivenby'the assemblypi- Fig. 41 'when positionedrtherewith;

Fig. -4 -an enlarged wertical sectional viewk oi the upper 1portion ofthe apparatus shown 2in Fig. `1';

f Fig. 5 -is a side -elevationalfview -of the upper portion -of Fig. -4showing certain-valve operating mechanism `in further'detaih fFig. -61`is Va 'sectional view 4taken Vsubstaritial-ly alongline 46 -of Figfll;J

Fig. '7 is a sectional view partly brokenfaway.

taken substantiallyalong-line T.-JI of Figi;

Fig. I8 is a 'vertical sectional view taken substantially-alongline 8-f8of Fig 4v; and

iFigsQ is a yvertical sectional viewlcorresponding to'Fig. 4,-b1 1tshowing analternative Vernbcdiment of the invention.

Referring tothe drawings infurtherdetail'and more yparticularly to `thecore Aas tshown-1in r-Fig. 2, it first noted that f-this core may sbegof .afwell known construction, except that lthe Yupper sectionI-*ithereof formedion its "upperfendiwith a portion ii6 'of enlargeddiameter.` "The upper rim Vof this :latter `lportion iis surrounded by-a-reinforcing ring or the like Il welded thereon and having atoppositely spaced positions two pairs of lugs or the like i8, I8'between which lifting links are received as hereinafter described. Withthe embodiment of the invention shown in Fig. 9 and as hereinafterdescribed, the upper end of the core does not need to be formed with aportion of enlarged diameter.

Referring now particularly to Figs. 1 and 4, the hammer assembly asshown comprises a body member 2B which includes an upper cylinder 2l ofrelatively large diameter and a lower cylinder portion 22 of smallerdiameter, these cylinder portions respectively containing pistons 2i and22 of corresponding sizes. These pistons are integral with or rigidlymounted upon a single piston rod 23 having a lower portion 23aterminating in a tapered end 23h tted within a corresponding cavity inthe upper end of a ram 24 (Fig. l). This tapered end is locked inposition within the ram by a transverse pin as indicated at 25.

` It will be noted that the lower and smaller cylinder portion of thehammer as well .as the ram are received within the working portion ofthe core l which is of normal diameter, whereas the lower part at leastof the larger cylinder portion of the hammer is received in the enlargedportion I6 of the core. As will be noted from the upper portions ofFigs. 2 and 3, this enlarged portion is intended in use to be locatedabove the upper end of the pile shell, that is, above the normal workingparts of the core.

The lower end ofthe smaller cylinder portion 22 of the hammer (Fig. 4)is closed oir by an annular member 26 which is secured and sealed inplace as by the use of a plurality of bolts 2l. The piston rod portion23a reciprocates within the central aperture and this member 26. A ramguide cylinder 28 is secured as by welding about the lower rim of themember 26 and serves as a cylinder through the lower end of which theram reciprocates when actuated. This ram guide cylinder also serves inconjunction with the body member to enclose and retain together thehammer and ram assembly when same is withdrawn from the core.

VAt a position just above the ram 24, a thick rubber bumper 30 encirclesthe piston rod portion 23a. This bumper may be in the form of a splitring of ilexible rubber which may be put into place, or readily removedfor replacement when desired, through a hand hole 3| formed in the sidewall of the ram guide cylinder (Fig. 1). The purpose of this bumper isto cushion the upper end of the ram with respect to the lower l surfaceof the member 26 when the hammer is being used in such a way as to drive(i. e. to pull) the core up out of the pile shell, if the core, afterdriving the shell, should become jammed as it sometimes does againsteasy upward removal by the crane.

As shown in Fig. 1, the ram 24 is at its position of impact and forreasons hereinafter explained, the impact is preferably applied againsta cap block assembly 32 of the type disclosed in U. S. patent toKinneman No. 2,184,745. 'Ihis type of cap block comprises upper andlower rigid members as at 33, 33 between which are located a stack ofso-called Belleville washers or the like 34 to provide an assembly whichwill cushion the impact to a predetermined degree which does not varymaterially even after receiving a large number of impacts. The lower endof this cap block rests upon an anvil block 35` forming a part of thecore structure. For the purposes of the particular hammer assemblyherein described, an important characteristic of this type of cap blockis that neither its normal vertical dimension before impact, nor itscompressed vertical dimension upon impact vary materially even after alarge number of impacts. For reasons hereinafter further explained, thisgreatly facilitates the proper actuation and timing of the valves of thedouble piston type of hammer herein disclosed, whereas if for example awooden cap block were used which would become more and more compressedafter repeated blows, then the position of impact of the ram withrespect to the core would change upon successive impacts so as torequire readjustment of the valves which control the timing of theimpact.

As indicated in the lower portion of Fig. 4, if found desirable, themember 26 on its upper surface may be formed or provided with a dripretaining ring 35 to catch condensate from steam in higher parts of thehammer. This condensate may be drawn away by removing a side plug 31when necessary and while the hammer is out of the core.

The steam passage and valve arrangements for controlling the operationof the hammer pistons will now be described. As in the case of doublepiston differential hammers heretofore used, the arrangement of thevalves is such that the steam supply is constantly connected to thespace between the pistons 2l', 22', whereas pressure is supplied to thespace above the large upper piston only during the greater part of thedown stroke and momentarily during the final part of the upstroke tocushion the nal upward movement. That is, just before the moment ofimpact, the steam pressure in the space above the upper piston isreleased and a passage from this space remains open to exhaust until theupstroke is nearly completed, whereupon pressure is again admitted abovethe piston 2 I to cushion and stop the upstroke. Admission of the iiuidpressure above the upper piston thereafter is continued and acts withthe aid of gravity to force the piston assembly down again, the activeand e'ective piston area then being equivalent to the area of piston 22.(That part of the area of piston 2| which is in excess of the area ofpiston 22 will have the same pressure thereon both above and below andthus will be ineiective in contributing force to the downstroke; andthat part of the area of the piston 2i' corresponding to the area ofpiston 22 will be subject to pressure on the upper side and this will beeffective together with gravity in causing the downstroke, since theunderside of piston 22 is not under pressure.)

The main control valve may preferably be of the Corliss type mounted onthe top of the hammer within an extension portion 23a of the body of thehammer. As shown in Fig. 8, this valve may comprise a cylindrical member38 formed on its side with a passage 39 adapted either to connect asteam inlet passage 40 with a passage 4l entering the larger cylinder orfor connecting the passage 4l with an exhaust passage 42. As shown inFigs. 4 and 5, a cam or lever member 43, is adjustably secured to oneend of the valve member 38, this lever member being adapted to beoperated by a, reciprocating rod 44 which passes through a suitablestufhng box down into the larger cylinder space 2 I. During the greaterpart of the upstroke, the valve member 38 will be in a position so thatits passage 39, as indicated by dotted lines in Fig. 8, will connect thepassage pin 69 or by other suitable means. Normally this buttery valveis positioned as indicated by full lines in Fig. 6 so as to offer nosubstantial restriction to the passage of steam into and through thevalve member 38 to the large cylinder. However, when it is desired tohave the hammer impart an upward impact, then the butterfly valve ismoved to the angle indicated by dotted lines in Fig. 6, thereby somewhatrestricting the admission of pressure. This will not only reduce thecushioning effect at the end of the upstroke to a sufficient degree topermit the bumper to strike an upward blow against the hammer assembly,but also, during the subsequent downstroke of the hammer, the admissionof fluid pressure will be so restricted that the hammer will not impartstrong downward impacts` As above noted, the cap block 32 against whichthe ram impact is imparted (lower part of Fig. i) should be of a typewhich does not progressively change its normal vertical dimensions asthe result of repeated impacts. The advantage of a cap block of thistype will now be apparent after considering the above description of thecontrol valve and steam passage arrangements. That is, assuming that acap block were used of a type such, for example, as of wood, which wouldbecome pounded successively to smaller and smaller vertical dimensions,then the location with respect to the core at which the impact takesplace will move downward somewhat with each succeeding blow.Consequently either the timing of the cut olf of the pressure above thelarger piston would have to be changed, or else the maximum possibleperiod of maintenance of such pressure for most effective action of thehammer will be decreased. Any step-by-step shifting of the timing of thevalves would, of course, involve complicated and possibly undependablemechanism. Also, if a wooden cap block` is used, there will not only bea variation in the force of successive blows, but also the ram will tendto damage the remainder of the hammer assembly because of over-strokingunless the wooden block is changed at inconveniently frequent intervals.It may further be noted that if the ram were to impart its impactdirectly to the anvil block or directly to any other solid member, thenno cushioning effect would be provided and severe destructive shockswould be imparted to the piston and ram assembly and other parts. Butwith the type of cap block above disclosed, all such diiliculties arereadily avoided.

With all of the embodiments of the invention it will be apparent that anassembly is provided such as to permit the powerful rapid-blow type ofdouble piston differential hammer to be used, and yet used in such a waythat only a small part of the height of the hammer and ram assemblyprotrudes above the core. And by placing the upper larger cylinder ofthis type of hammer above the working part of the core, this cylindercan readily be made as large as desired and hence in practice there isno denite limit to the weight of the ram which can be used. (The liftingpower of the hammer depends upon the pressure against the area of theunderside of the large piston minus the area of the small piston.) Theweight of the ram may be greatly increased if desired by increasing itslength, and yet a hammer with an upper piston sufficiently large to liftsuch a heavy ram can still be provided and largely contained in thecore, since the large cylinder part only of the hammer need be locatedabove the working part of the core where the diameter is limited by thediameter of the pile shell. It, therefore, becomes possible with thisinvention to use a ram as heavy as desired within reasonable limits andalso to increase greatly the number of blows per minute as compared withprior assemblies of single piston hammers within pile cores.

As above stated, with the embodiment of the invention shown in Fig. 9,the core 15 does not have to be provided with an enlargement at itsupper end. Instead the flange formation at 'I6 at the lower part of thelarger cylinder portion of the hammer may rest directly upon a rubbercushion ring H which in turn rests upon the upper end of the core 15.And with this embodiment the pistons as indicated at '18, 18 fortemporarily gripping the core, are located in the lower end portion ofthe smaller cylindrical part of the hammer, the fluid pressure passagefor controlling these pistons being indicated at 19 extending from anintake port within the upper end of the larger cylinder down to anannular passage 8| at the region of the piston 18, 'IB'. Theconstruction and operation of other parts of the embodiment of Fig. 9will be apparent from the above description of Fig. 4.

It may be noted that temporary gripping means in the form of pistonssuch as at 60, 60 of Fig. 4 and 18, 18 of Fig. 9 may be used for varioustypes of hammers other than the differential types here disclosed, butwhich are double acting and which may consequently tend to rise in acore or casing during a part of the cycle of operation, in the absenceof such gripping means.

Although certain particular embodiments of the invention are hereindisclosed for purposes of explanation, various further modificationsthereof, after study of this specication, will be apparent to thoseskilled in the art to which the invention pertains. 1Reference shouldaccordingly be had to the appended claims in determining the scope ofthe invention.

What is claimed and desired to be secured by Letters Patent is l. Thecombination comprising: a tubular pile core; a double pistondifferential type of uid pressure hammer located in said core; a ram insaid core beneath said hammer and connected to the piston rod thereof,the lower and smaller piston of the hammer being contained in a cylinderportion of external dimensions such that same is slidable within thenormal working portion of the core, and the upper and larger piston ofthe hammer being contained in a cylinder portion larger than, and abovethe normal working portion of the cor'e.

2. The combination comprising: a tubular pile core; a double pistondifferential type of fluid pressure hammer located in said core; and aram in said core beneath said hammer and connected to the piston rodthereof, the lower and smaller piston of the hammer being contained in acylinder portion of external dimensions such that same is slidablewithin the normal Working portion of the core, and the upper and largerpiston of the hammer being contained in a cylinder portion of largerdiameter than, and above the normal working portion of the core, saidhammer having control valve means for the pistons thereof located uponthe upper end of th larger cylinder portion.

3. A double piston differential type of uid pressure hammer and ramassembly adapted for telescopic assembly with tubular pile cores and thelike, comprising in combination: relatively large and smaller adjoiningVcylinder portions containing pistons` respectively of correspondingsizes and secured to a common piston rod, the smaller cylinder portionbeing lowermostl and having a tubular ram guide attachedl tovv anddepending-'from-the lower enclthereoi and an elongated ram in'said guidesecured at its'- upper end tti-said' piston, said smaller cylinderportion and said ramguide being adapted tobe slidably received withinthe working part of a pile core.

la The combination comprising: a tubular pile core having an upper endportion of enlarged diameter as compared with the diameter of the normalworking portion of the core; a double piston differential type of iluidpressure hammer located in said core; and a ram in said core beneathsaid hammer and connected to the piston rod thereof, the lower andsmaller piston of the hammer being contained in a cylinder portion ofexternal dimensions such that same is slidable within the normal workingportion of the core, and the upper and larger piston of the hammer beingcontained in a larger cylinder portion of external dimensions such thatsame is at least partially slidable within the enlarged core portion butnot into said working portion of the core.

5. A fluid pressure operated hammer adapted for telescopic assembly witha surrounding casing or the like, said hammer having iluid pressureoperated means in its side walls for frictionally gripping the interiorwalls of the casing or the like to prevent movement of the hammer withrespect to the latter.

6. A fluid pressure operated hammer adapted for telescopic assembly witha surrounding casing or the like, said hammer having fluid pressureoperated piston means in its side wall, movable transversely of the mainaxis of the hammer to frictionally grip the interior wall of the casingor the like, and conduit means extending from said p-iston means to thesame source of fluid pressure as provided to operate the hammer.

7. A double acting fluid pressure operated hammer adapted to be receivedin a casing or the like, said hammer having fluid pressure operatedmeans thereon for gripping the interior wall of the casing, andconnections for bringing the fluid pressure which operates the hammerduring a predetermined part of its stroke into communication with saidiluid pressure operated means to cause the latter to grip the casingduring said part of the stroke.

8. A double acting fluid pressure operated hammer adapted to be receivedin a casing or the like to be driven by the hammer, said hammer havingfluid pressure operated means thereon movable transversely of the axisof the casing for frictionally gripping the interior wall of the casing,and connections for bringing the fluid pressure which operates thehammer into communication with said fluid pressure operating means, saidconnections including means automatically to release pressure from saidfluid pressure operating means at a time close to the moment of impactof the hammer, thereby releasing the gripping action on the casing topermit the casing to be freely driven by the impact.

9. A double piston diierential type of uid pressure operated hammeradapted for telescopic assembly with a surrounding casing or the like,said hammer having uid pressure operated means in its side wall forfrictionally gripping the interior wall of the casing or tbe like, andconduit means for bringing said uuid pressure operated meansintocommunication with and under the control ofA the samef fluidv pressureas provided inthe larger cylinder of the diiferential hammer.

10. In combination: a fluid pressure' operated hammern of a type havingav piston and adapted to strike a downward blowy bythe action of uidpressure above suchY piston and havingv an automatically controlledvalvefor releasin'gjsuch 'pressure at a time close tol the momentofimpact;` av casing within which such hamm'erjis received, said; hammerhaving fluid" pressure means thereon foru grippingthe,r interior of;lthe casing; and. connections for bringiifigV saidj' fluid pressureoperating means into communication with, and for operation by, saidfluid pressure above the piston, to thereby cause said means to grip thecasing during the downstroke of the hammer until release of suchpressure.

11. The combination comprising: a tubular pile core; and a double pistondifferential type of fluid pressure hammer, the lower and smaller pistonof the hammer being contained in a cylinder portion slidably receivedwithin the core, the upper and larger piston of the hammer beingcontained in a cylinder portion larger than and at least partiallylocated above the normal working portion of the core.

12. The combination comprising: a tubular pile core; a double pistondiilerential type of fluid pressure hammer, the lower and smaller pistonof the hammer being contained in a cylinder portion slidably receivedwithin the core, the upper and larger piston for the hammer beingcontained in a cylinder portion too large to be received in the core;and a cushioning means interposed between -the upper end of the core andperipheral parts of the latter cylinder portion.

13. In combination: a fluid pressure operated hammer of a type having apiston and piston rod and adapted to strike a downward blow by theaction of fluid pressure above such piston and having an automaticallycontrolled valve for releasing such pressure at a predetermined timeclose to the moment of impact; a ram connected to the lower end of saidpiston rod; and a cap block beneath such ram adapted to impart blowsfrom the ram to an anvil block, said hammer, ram and cap block beingadapted to be received in a tubular casing connected to the anvil blockto be driven thereby, said cap block comprising a plurality ofsuperposed members, which are resilient to a predetermined limiteddegree in the direction of the axis of the ram, and which serve tomaintain the cap block normally with a substantially constant verticaldimension prior to each impact.

14. In combination with a tubular pile core: a double pistondifferential type of ilud pressure hammer at least partially received insuch core and connected to the upper end thereof by linkage means, saidhammer having automatically controlled valve means and connections formaintaining substantially constant pressure between the pistons and formaintaining pressure above the larger piston during the greater part ofthe downstroke, and the final part of the upstroke for cushioningpurposes; a piston rod connected to the hammer pistons and extendingdownwardly therefrom; a ram connected to the lower end of said pistonrod; a bumper interposed between said ram and the lower part of the bodyof the hammer; and valve means for limiting the admission of pressurefluid above the larger piston, thereby to limit the cushioning of theupstroke whereby the hammer will strike anupward blow for imparting anupward blow through such linkage means to the core. Y

l5. A double piston diierential type of uid pressure operated hammerhaving interconnected upper and lower pistons, contained respectively inrelatively large and smaller cylinders, and valve means and connectionsfor maintaining substantially a constant pressure between saidpistonsand for maintaining pressure above the larger piston during the greaterpart of its downstroke and the final part of its upstroke for cushioningpurposes, said valve means including a push rod extending into the uppercylinder and positioned to be actuated by the larger piston as itapproaches the limit of its upstroke to then actuate the valve means toadmit pressure above the larger piston, and a fluid pressure operatedmeans connected to receive operating uid pressure from the space betweenthe pistons at a time near the end of the downstroke for restoring saidvalve means 10 to closed position.

EDWARD A. SMITH.

No references cited.

